Bicycle stem



FIG. 1 is a top perspective view showing our new design, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a bottom plan view;

FIG. 3 is a top plan view;

FIG. 4 is a side plan view as shown from the left in FIG. 3;

FIG. 5 is a front elevational view; and,

FIG. 6 is a right elevational view. 

The ornamental design for a bicycle stem, as shown and described. 